Sewing-machine trimmer



(No Model.) 2 Sheets-Sheet 1.

E. B. ALLEN.

SEWING MACHINE TRIMMER. No. 598,334. Patented Feb. 1,1898

(No Model.) 2 SheetsSheet 2 E. B. ALLEN. SEWING MAOHINE TRIMMER.

No. 598,334. I Patented Feb. 1,1898.

7, IIIIl/IIIA FFlQE.

ATENT EDWARD B. ALLEN, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, OF NEW JERSEY.

SEWING-MACHINE TRIMMERA SPECIFICATION forming part of Letters Patent No. 598,334, dated February 1, 1898. Application filed June 15, 1897. Serial No. 641,075. (No model.)

To all whom it may concern:

Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Sewing-Machine Trimmers,

of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to certain improvements on the sewing-machine trimmer embraced by my United States Patent No.

579,632, issued March 30, 1897, the object of the present invention being to improve the shear-trimmer, to provide means for more effectively preventing lint or trimmings from working down through the trimmer slot or opening in the work-plate than could be done with my former construction, and also to provide an adjustable feed-dog section which will be moved laterally with the trimmer when the latter is adjusted to vary the distance between the line of trimming and the line of stitching, so that there will be no difficulty in chaining off the last stitches of a seam when the trimmer is adjusted farthest from the needle of the machine.

In the accompanying drawings, Figure 1 is a plan view of the lower part of a Singersingle-thread chain-stitch sewing-machine embodying my invention. Fig. 2 is a similar view of the same with the work-plate removed. Fig. 3 is an end View of the same with the work-plate in section. Fig. 4 is a section on line 4 4 of Fig. 2. Fig. 5 is a detail sectional view of the feed-dog and of the adjustable device for securing the lower blade in place.

A denotes aportion of the frame of the machine, and B the rotating driving-shaft, carryin g the single-thread chain-stitch looper b and the feed and trimmer operating eccentrics.

O is the feed-bar, carrying the feed-dog c, said bar being jointed at c to the upwardlyextending arms 61 of a feed-operating rockshaft D, having at its rear end an arm 01, to which is adjustably connected one end of a pitman d, the other end of which is provided with a strap d surrounding an eccentric on the shaft B, and which eccentric, through said pitman imparts rocking or feeding movements to said shaft D. The feed-bar is forked at c to embrace a feed raising and lowering eccentric on said shaft B.

E is the rocking trimmer-shaft, mounted, as before, in the feed-bar O, carrying the feeddog a, and provided with a rigid arm 6, forked to embrace an eccentric b on the shaft B to impart rocking movements to said trimmershaft. Said trimmer-shaft is also provided with a rigid arm or plate (2, (preferably formed rigid therewith,) tapped at its upper end for the reception of set-screw 6 by means of which and the clamping-plate and guard e the segmental upper shear blade or knife e is held in any desired position of adjustment, said blade being pivotally mounted on the said shaft E, so that its position may be changed to compensate for wear. The lower trimmer-blade e is also pivotally mounted on the shaft E, so that it may be adjusted to compensate for wear, and is normally held rigid with or stationary relative to the feedbar and feed-dog. To this end a rear extension e of said blade is provided with a slot e to embrace an adjustable hollow pin or sleeve '6, formed integral with and extending outward from a slide a movable in an undercut groove 0 formed in the side of the feed-bar C, said hollow pin or sleeve being tapped for the reception of a set-screw e", which impinges, to hold the said slide and sleeve in place, against the bottom of the slot 0 F is a sliding block movable in a suitable guideway in the frame of the machine and provided with a notch or recess f, entered by a depending lug e formed on the hub e of the arm 6 of the rock-shaft E. The block F is provided with a depending lug f, entering an annular groove formed between flanges g on an adjusting-screw G, tapped in the machine-frame and provided with a milled head b which it may be readily turned to adg 3 just the trimmer rock-shaft E and the trimmer-blades 6 and a", mounted on said shaft, laterally or toward and from the needle. The

block F and the trimmer connected therewith are held in any desired position of adjustment against accidental displacement by any suitable retaining device, which in the present instance consists simply of the friction-washer f placed beneath the head of the steadying or holding screw f H is a sliding lint-guard plate suitably mounted to be moved back and forth or from and toward the needle on the work-plate A, the forward end of said guard-plate being closely adjacent to the arm or plate 8 of the trimmer-shaft E, so that there will be no appreciable opening for the passage of lint between the forward end of said guard-plate and the arm or plate e. The sliding block F is provided with an upwardly-projecting lug f which enters a slot. in the plate H, so that the latter will be adjusted back and forth with the trimmer, which is movable with said block, as has been described. This adjustable lint-guard H is similar to the lint-guard I of my Patent No. 579,632 referred to; but in the machine shown by said patent no provision was made for keeping the front side of the slot in the work-plate closed when the trimmer was adjusted away from the needle. This omission is remedied in the present in stance by extending the lint-guard around to the front or outer side of the trimmer, and for convenience in getting at the trimmerblades when it is necessary to remove the same for sharpening this extension of the lint-guard consists, preferably, of an independent plate H, removably mounted on the plate H by means of the arm h, having holes to engage the upper ends of the screws h, which pass through slots in the work-plate A, and between the lower side of which workplate and the heads of said screws frictionwashers h2 are preferably placed to give the plate H a frictional sliding connection with the work-plate.

To keep the rear part of the slot in the work-plate, into which the rear part of the blade 6 extends, closed when said blade has been adjusted so far forward (when said blade has been partly used up) that it will not fill said slot, the clamping-plate 6 by which the said blade is held in place, is extended down to and a little below the upper surface of the work-plate A, this clamping-plate thus serving also as a lint-guard at this point.

It is desirable that a portion of the feeddog should work on the side of the needle away from the operator or on what (considering the progress of the work) may be termed the front side of the needle, and it is also desirable, to effect the chaining off of the end of the seam properly at all times, that there should be no opening between the lower trimmer-blade and the feed or other support for the work adjacent to said blade. To keep the slot in the work-plate closed at the point referred to, I have provided an adj ustable feed-dog 0 carried by an arm a, which encircles the trimmer-shaft E. The auxiliary feed-dog c is connected with the main feeddog 0 by means of a lip on the former engaging an undercut notch or groove in the latter, as shown in Fig. 3, and said auxiliary feed-dog is also connected with the feed-bar through the arm 0 the rear end of which encircles the trimmer-shaft E, mounted in said feed-bar, and thus the said auxiliary feeddog willmove up and down and back and forth with the feed-bar and main feed-dog. The arm 0 is pressed against the lower trimmer-blade e and the said lower blade is pressed against the upper blade 6 and the latter held against the arm eby the spiral spring 6 interposed on the shaft E between the said arm 0 and a nut e on the outer end of said shaft. Thus the sectional or auxiliary feed-dog 0 while moving up and down and back and forth with the main feed-dog c is adapted to be adjusted back and forth laterally with the trimmer-blades and will always be held in contact with the lower trimmer-blade, so as to keep the slot in the workplate closed adjacent to said blade when the trimmer is adjusted away from the needle.

The operation of my improved trimmer is essentially the same as that shown and described in my patent hereinbefore referred to. Both blades of the trimmer being mounted on\ the feed-bar follow the movements thereof, the rocking upper blade closing to effect the cutting when the feed is moving forward to advance the work, and the entire trimmer, including both blades and the trimmer-operating rock-shaft, being adjustable toward or from the needle to vary the'distance between the line of stitching and the line of trimming, either when the machine is in operation or at rest, as in my former patent, while the trimmer-slot in the work-plate is at all times kept closed by the lint-guards H, H, and e surrounding the trimmer-blades.

Having thus described my invention, I claim and desire to secure by Letters Patent- 1. The combination with the stitch-forming mechanism of a sewing-machine, of a laterally-adjustable shear-trimmer device, a workplate slotted for the reception of said sheartrimmer device, and a laterally-adjustable lint-guard extending closely adjacent to both sides of said shear-trimmer to close said slot, and connections between said trimmer and said guard whereby the latter will be adjusted coincidently with the former to keep the said slot closed at all times on both sides of the trimmer regardless of the position of adj ustment of said trimmer. I

2. The combination with the stitch-forming mechanism of a sewing-machine, of a laterally-adjustable trimmer, the guard-plate H connected with said trimmer to be laterally adjustable therewith, and the independent guard-plate H removably attached to said plate H and adjustable therewith and with said trimmer.

3. In a sewing-machine trimmer, the com-' IIO tive to said shaft, and both of which are pivotally mounted on said shaft so that they may be adjusted about the same to compensate for wear, and means for securing both of said blades in any desired positions of adjustment.

4:. The combination with the stitch-forming and feed-operating mechanism of a sewingmachine, of a trimmer which is laterally adjustable relative to said stitch-forming mechanism, and a feed-dog which is laterally adjustable with said trimmer.

5. The combination with the stitch-forming mechanismof a sewing-machine, of a laterally-adjustable trimmer, a feed-bar and its operating mechanism, a feed-dog which is fixed relative to said feed-bar, and a second feed-dog which is connected to and laterally adjustable with said trimmer.

6. The combination with the stitch-forming and feed-operating mechanism of a sewingmachine, of a laterally-adjustable shear-trimmer comprising upper and lower blades, and a laterally-adjustable feed-dog placed closely adjacent to said lower blade and connected with said trimmer to be laterally adjustable therewith.

7. The combination with the stitch-forming mechanism of a sewing-machine, of a laterally-adjustable shear-trimmer comprising upper and lower blades, a feed-bar and its op- 3o crating mechanism, a feed-dog which is fixed relative to said feed-bar, and a second feeddog placed closely adjacent tosaid lower blade and connected with said trimmer to be laterally adjustable therewith.

In testimony whereof I affix my signature in presence of two witnesses.

EDWARD B. ALLEN.

Witnesses:

HENRY CALVER, JosErH F. J AQUITH. 

